Thank you so much for your help. I'm thinking that "no IPv4 address assigned" has something to do with it. I'm not on a Mac. Below I have included both the "sudo tcpdump -v" and "sudo tcpdump -vv".
amnesia@amnesia:~$ sudo tcpdump -v [sudo] password for amnesia: tcpdump: WARNING: eth0: no IPv4 address assigned tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes 16:08:11.679122 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328) 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fc:aa:14:57:63:6f (oui Unknown), length 300, xid 0xfa0dee58, secs 7, Flags [none] Client-Ethernet-Address fc:aa:14:57:63:6f (oui Unknown) Vendor-rfc1048 Extensions Magic Cookie 0x63825363 DHCP-Message Option 53, length 1: Discover Parameter-Request Option 55, length 17: Subnet-Mask, BR, Time-Zone, Default-Gateway Domain-Name, Domain-Name-Server, Option 119, Hostname Netbios-Name-Server, Netbios-Scope, MTU, Classless-Static-Route NTP, Classless-Static-Route, Classless-Static-Route-Microsoft, Option 252 NTP 16:08:12.337499 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 104) fe80::920d:cbff:fe02:28c1 > ip6-allnodes: [icmp6 sum ok] ICMP6, router advertisement, length 104 hop limit 64, Flags [other stateful], pref medium, router lifetime 1800s, reachable time 3600000s, retrans time 1000s prefix info option (3), length 32 (4): 2601:199:c000:c58c::/64, Flags [onlink, auto], valid time 235738s, pref. time 235738s rdnss option (25), length 24 (3): lifetime 3s, addr: 2001:558:feed::1 rdnss option (25), length 24 (3): lifetime 3s, addr: 2001:558:feed::2 source link-address option (1), length 8 (1): 90:0d:cb:02:28:c1 16:08:15.337694 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 104) fe80::920d:cbff:fe02:28c1 > ip6-allnodes: [icmp6 sum ok] ICMP6, router advertisement, length 104 hop limit 64, Flags [other stateful], pref medium, router lifetime 1800s, reachable time 3600000s, retrans time 1000s prefix info option (3), length 32 (4): 2601:199:c000:c58c::/64, Flags [onlink, auto], valid time 235735s, pref. time 235735s rdnss option (25), length 24 (3): lifetime 3s, addr: 2001:558:feed::1 rdnss option (25), length 24 (3): lifetime 3s, addr: 2001:558:feed::2 source link-address option (1), length 8 (1): 90:0d:cb:02:28:c1 16:08:15.405947 IP (tos 0x20, ttl 114, id 13995, offset 0, flags [DF], proto UDP (17), length 145) 99.132.232.166.46472 > 10.0.0.14.14299: UDP, length 117 16:08:18.337887 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 104) fe80::920d:cbff:fe02:28c1 > ip6-allnodes: [icmp6 sum ok] ICMP6, router advertisement, length 104 hop limit 64, Flags [other stateful], pref medium, router lifetime 1800s, reachable time 3600000s, retrans time 1000s prefix info option (3), length 32 (4): 2601:199:c000:c58c::/64, Flags [onlink, auto], valid time 235732s, pref. time 235732s rdnss option (25), length 24 (3): lifetime 3s, addr: 2001:558:feed::1 rdnss option (25), length 24 (3): lifetime 3s, addr: 2001:558:feed::2 source link-address option (1), length 8 (1): 90:0d:cb:02:28:c1 16:08:21.338085 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 104) fe80::920d:cbff:fe02:28c1 > ip6-allnodes: [icmp6 sum ok] ICMP6, router advertisement, length 104 hop limit 64, Flags [other stateful], pref medium, router lifetime 1800s, reachable time 3600000s, retrans time 1000s prefix info option (3), length 32 (4): 2601:199:c000:c58c::/64, Flags [onlink, auto], valid time 235729s, pref. time 235729s rdnss option (25), length 24 (3): lifetime 3s, addr: 2001:558:feed::1 rdnss option (25), length 24 (3): lifetime 3s, addr: 2001:558:feed::2 source link-address option (1), length 8 (1): 90:0d:cb:02:28:c1 16:08:24.338281 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 104) fe80::920d:cbff:fe02:28c1 > ip6-allnodes: [icmp6 sum ok] ICMP6, router advertisement, length 104 hop limit 64, Flags [other stateful], pref medium, router lifetime 1800s, reachable time 3600000s, retrans time 1000s prefix info option (3), length 32 (4): 2601:199:c000:c58c::/64, Flags [onlink, auto], valid time 235726s, pref. time 235726s rdnss option (25), length 24 (3): lifetime 3s, addr: 2001:558:feed::1 rdnss option (25), length 24 (3): lifetime 3s, addr: 2001:558:feed::2 source link-address option (1), length 8 (1): 90:0d:cb:02:28:c1 16:08:25.295910 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328) 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fc:aa:14:57:63:6f (oui Unknown), length 300, xid 0xfa0dee58, secs 21, Flags [none] Client-Ethernet-Address fc:aa:14:57:63:6f (oui Unknown) Vendor-rfc1048 Extensions Magic Cookie 0x63825363 DHCP-Message Option 53, length 1: Discover Parameter-Request Option 55, length 17: Subnet-Mask, BR, Time-Zone, Default-Gateway Domain-Name, Domain-Name-Server, Option 119, Hostname Netbios-Name-Server, Netbios-Scope, MTU, Classless-Static-Route NTP, Classless-Static-Route, Classless-Static-Route-Microsoft, Option 252 NTP
amnesia@amnesia:~$ sudo tcpdump -vv [sudo] password for amnesia: tcpdump: WARNING: eth0: no IPv4 address assigned tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes 16:16:18.369060 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 104) fe80::920d:cbff:fe02:28c1 > ip6-allnodes: [icmp6 sum ok] ICMP6, router advertisement, length 104 hop limit 64, Flags [other stateful], pref medium, router lifetime 1800s, reachable time 3600000s, retrans time 1000s prefix info option (3), length 32 (4): 2601:199:c000:c58c::/64, Flags [onlink, auto], valid time 235252s, pref. time 235252s 0x0000: 40c0 0003 96f4 0003 96f4 0000 0000 2601 0x0010: 0199 c000 c58c 0000 0000 0000 0000 rdnss option (25), length 24 (3): lifetime 3s, addr: 2001:558:feed::1 0x0000: 0000 0000 0003 2001 0558 feed 0000 0000 0x0010: 0000 0000 0001 rdnss option (25), length 24 (3): lifetime 3s, addr: 2001:558:feed::2 0x0000: 0000 0000 0003 2001 0558 feed 0000 0000 0x0010: 0000 0000 0002 source link-address option (1), length 8 (1): 90:0d:cb:02:28:c1 0x0000: 900d cb02 28c1